Methods of bromination of cyclododecatriene in solvent(s) to produce hexabromocyclododecane ("HBCD" hereinafter) particles are known. For example, see U.S. Pat. No. 3,558,727 (Jenkner et al). After the bromination reaction, the reaction mass can be subjected to separation techniques (e.g. filtration, centrifugation or decantation) to produce a recovered mass, e.g. wetcake, which is predominantly HBCD particles but which can additionally contain contaminants to this product, e.g. residual bromides such as hydrogen bromide and elemental or ionic bromine, dodecyl halides such as tetrabromocyclododecane, and solvents. For example, see U.S. Pat. No. 3,558,727 (Jenkner et al) and UK No. 2,205,830 (Hermolin et al).
In the manufacture of HBCD, it is beneficial to provide solid HBCD particles in forms which are easily recoverable through the separation techniques used. For example, larger particle sizes such as that provided by agglomerization or crystal growth will be more readily recoverable by these techniques and therefore result in a larger yield. Such methods are disclosed, for example in
U.K. No. 2,205,830 (Hermolin et al) PA1 D.E. No. 3,120,621 (Jenkner et al) PA1 U.S. No. 3,652,688 (Dlechowski et al) PA1 U.S. No. 3,833,675 (Newcombe et al) PA1 (i) solid particles comprising HBCD; PA1 (ii) liquid organic components, i.e. solvents; and PA1 (iii) contaminants comprising one or more members of a group consisting of dodecyl bromides, hydrogen bromide, alkyl bromides and bromine. PA1 (1) forming an admixture of the above-said composition and water; PA1 (2) heating this admixture for a time at a temperature and a pressure sufficient to remove at least a portion of the liquid organic components from this admixture and to form agglomerates with at least a portion of the solid particles; and PA1 (3) recovering from the admixture a product comprising the particles and the agglomerates; PA1 wherein the forming and the heating are effective to enhance the removal of at least a portion of one or more of the members of the group of contaminants during this heating and/or recovering so as to reduce the concentration of the members of contaminants in the product. PA1 (a) forming an HBCD wetcake admixture with wetcake and water; PA1 (b) heating the HBCD wetcake admixture to effect agglomerization; and PA1 (c) neutralizing acidity associated with the HBCD. PA1 (a) forming a wetcake slurry with wetcake and water; PA1 (b) neutralizing acidity associated with the solid particles in the slurry; PA1 (c) steam distilling the slurry; PA1 (d) separating solid particles from at least a portion of the slurry; and PA1 (e) washing the solid particles.
There continues to be a need for methods directed to producing HBCD particles with reduced residual bromides and other contaminants and with enhanced filterability.